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A comment on Bitcoin mining hash rate drops as blackouts instituted in China. Parent comment

Re:Bitcoin mining hash rate drops as blackouts instituted in... by sillysaurusx on Sunday April 18, 2021 @02:47AM (#26850345)
Oh, you're probably right. It seemed related because the further back an adversary wanted to roll back to, the more hash power they'd need to get ahead. But it's a different category.

I wonder if there has been an analysis of how much hash power you'd need relative to how many blocks in the past you'd want to roll back.

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Re:Bitcoin mining hash rate drops as blackouts instituted in... by Thorrez on Sunday April 18, 2021 @06:25PM (#26857081)
That analysis is actually in the original 2008 bitcoin whitepaper:

https://bitcoin.org/bitcoin.pdf

If you have 51% of the power, you can roll back everything if you spend enough time on it. If you have 30%, you have a 4% chance of being able to catch up from 10 blocks behind, even if you spend infinite time on that specific fork.

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